Regular infusions of blood plasma from young donors could be used to treat patients with Alzheimer’s disease, a medical conference in Boston was told on Saturday.

Researchers said that their study showed transfusions were safe, had no serious side effects and hinted that infusions could lead to benefits in patients’ memory and thinking.

Infusions of blood plasma – the liquid, cell-free part of blood – are used in surgery and to treat conditions such as liver disease. In addition, research on mice has shown that regular plasma infusions from young mice improves memory in older mice.

The new trial, sponsored by Stanford University, was set up to build on these findings and to test the safety and feasibility of administering blood plasma from younger people to those living with Alzheimer’s disease.

The team, who were speaking at the Clinical Trials on Alzheimer’s Disease conference in Boston, revealed that they worked with 18 volunteers with mild to moderate Alzheimer’s disease who received four weekly infusions of either a placebo saline solution or blood plasma from donors aged between 18 and 30. Then there was a six week “wash-out” period during which participants did not receive either infusion. The researchers then switched the infusions that participants received so that those who previously had plasma received the placebo and vice versa. The participants also took part in memory and thinking tests and assessments of their ability to carry out everyday tasks.

“The research points to potential signs of improvement but we need to see much larger studies before we can tell if this approach could help improve the lives of people living with Alzheimer’s,” said Dr Carol Routledge, director of research at Alzheimer’s Research UK. “Alzheimer’s is the most common cause of dementia, affecting half a million people in the UK, and we urgently need treatments capable of stopping the disease in its tracks.”